Part A
AD7740KRMZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3022 PCS
- Package
- TSSOP-8
- Series
- PMIC - V-F and F-V Converters
Replacement verdict
Compatible functional replacement candidate
The AD7740KRMZ is a functionally compatible replacement candidate for the AD7740KRM, sharing the same synchronous voltage-to-frequency converter core, 8-pin MSOP package, and supply range. The primary distinction is RoHS compliance, with the KRMZ suffix denoting the lead-free, RoHS-compliant variant. Designers should confirm solder profile and compliance requirements before substituting in production.
Function and Output Type
High match
Package Type
High match
Supply Voltage Range
High match
RoHS Compliance
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7740KRMZ | AD7740KRM | Why it matters |
|---|---|---|---|
| Manufacturer | Analog Devices Inc. | Analog Devices Inc. | Same manufacturer ensures consistent design IP and support. |
| Function | Voltage-to-frequency converter (synchronous VFC) | Voltage-to-frequency converter (synchronous VFC) | Identical core function is required for direct substitutability. |
| Package / Case | 8-TSSOP / MSOP | 8-TSSOP / MSOP | Same footprint allows drop-in board replacement without layout changes. |
| Supply Voltage Range | 3.0 V to 5.25 V | 3.0 V to 5.25 V | Matching supply range ensures compatibility with the same power rail. |
| Output Frequency Range | Up to 500 kHz | Up to 500 kHz | Same output range preserves system resolution and timing behavior. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature rating supports the same application environments. |
| RoHS / Lead Status | RoHS compliant, lead-free | Non-RoHS, contains lead | RoHS status affects regulatory compliance and solder process compatibility. |
| Part Number Suffix Meaning | Z denotes RoHS-compliant version | No Z suffix, legacy non-RoHS version | The suffix distinguishes compliance grade, which is critical for procurement and assembly. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7740KRMZ | AD7740KRM |
|---|---|---|
| Part Status | Active | Obsolete |
| Type | Voltage to Frequency | Voltage to Frequency |
| Frequency - Max | 1 MHz | 1 MHz |
| Full Scale | ±50ppm/°C | ±50ppm/°C |
| Linearity | ±0.012% | ±0.012% |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What is the difference between the AD7740KRMZ and the AD7740KRM?
The AD7740KRMZ and AD7740KRM are functionally identical synchronous voltage-to-frequency converters (VFCs). The primary difference is the package and ordering suffix: the AD7740KRMZ is supplied in a RoHS-compliant, lead-free 8-lead MSOP (RM-8) package, while the AD7740KRM is the non-RoHS (leaded) version of the same 8-lead MSOP device. Both share the same electrical specifications and operating temperature range.
Are the AD7740KRMZ and AD7740KRM electrically interchangeable?
Yes. Both parts are the same AD7740 VFC die in the same 8-lead MSOP footprint, with identical pinout, supply range (3.0 V to 5.25 V), and specified performance. The only distinction is RoHS/lead-free compliance, so they are electrically and functionally interchangeable in a given design.
What is the pinout of the AD7740KRMZ and AD7740KRM?
Both devices use the same 8-lead MSOP pinout: Pin 1 = REFIN, Pin 2 = VIN, Pin 3 = CLKIN, Pin 4 = GND, Pin 5 = CLKOUT, Pin 6 = FOUT, Pin 7 = VDD, Pin 8 = BUF. Because the pinout is identical, the PCB land pattern is the same for both variants.
What is the supply voltage and operating temperature range for these parts?
Both the AD7740KRMZ and AD7740KRM operate from a single supply of 3.0 V to 5.25 V and are specified over the commercial temperature range of 0°C to +85°C (the K grade). These parameters are identical for both variants.
Which variant should be selected for a new RoHS-compliant design?
For new designs requiring RoHS compliance, the AD7740KRMZ (lead-free, RoHS-compliant MSOP) should be selected. The AD7740KRM is the non-RoHS version and is generally not recommended for new RoHS-restricted products.
Do the AD7740KRMZ and AD7740KRM share the same datasheet specifications?
Yes. Both variants are covered by the same Analog Devices AD7740 datasheet, which specifies the synchronous VFC performance, linearity, clock input, and buffered reference characteristics. The datasheet documents the ordering options including the RoHS-compliant Z suffix and the non-RoHS version.
Can the AD7740KRM be replaced by the AD7740KRMZ without design changes?
Yes, in most cases. Since both are the same die in the same 8-lead MSOP package with identical pinout and electrical specifications, the AD7740KRMZ can directly replace the AD7740KRM on an existing PCB. The only consideration is that the Z suffix denotes lead-free/RoHS construction, which may affect soldering process requirements.